G. Klinger

About the usability of a photovoltaic module to monitor air pollution

The responsivity by means of the quotient of photo-current and incident global light intensity of a solar module situated in central Vienna was analyzed during a period where an ash cloud of volcanic origin was spread over central Europe in spring 2010. A timely coincidence between anomalies of the registered responsivity and the concentration of ash particles in the air was found. However due to the lack of reliable directly observed particle concentration no correlation could be established.

A study of vibration induced distortion on the performance of photovoltaic converters

Mechanical vibrations of a solar module cause oscillations in the orientation of the module towards the sun, resulting in a low frequency a.c. current component at the modules terminals. We have investigated this effect and performed model calculations in order to estimate the influence on the feed back control of a converter.

Local Characterization Of Multicrystalline Silicon Wafers And Solar Cells

The current voltage characteristics of multicrystalline solar cells with individually de- signed front contact grids under different bias light conditions in the temperature range of 300 K to 340 K were investigated. Cells with a grid placed predominately on grain boundaries exhibit higher conversion efficiencies than cells where a great portion of the grid covers crystallites. The diode loss current observed for the first type of cells is governed by a thermal activation energy which is about 30 meV larger than found for other cells. This is attributed to a local increase of the recombination center density within grain boundaries.

Active Thermography Applied for Quantitative Determination of Stomatal Resistance

Abstract. Based on an extension of the theory of energy balance the stomatal resistance of leaves in vivo is calculated by using temperature rise and fall times (thermal time constants) which are caused by a sudden change of irradiation intensity. The change in the irradiation was performed by turning on/off a red laser. To measure the temperature changes a commercial IR-camera was employed. Experiments were performed under laboratory conditions (monitoring of air temperature and humidity, no wind). As modelmaterial leaves of basil were taken. The applicability of the new method is demonstrated.

Investigations of AC-DC Transfer Standards in the Near-Infrared Spectral Range

The purpose of this work was (a) to develop an experimental set-up which is capable to record the time dependent temperature fluctuations of single junction thermal converters due to low-frequency ac currents by using an IR photo detector and (b) a characterisation of the local and temporal temperature behaviour of shunts for the ac current measurements with a thermocamera